“I don’t know why it’s not on the front page of the newspapers,” replied Jennifer Marohasy.

The subject of the pair’s wrath is the Bureau of Meteorology (BoM) — the Australian government’s weather bureau.

Specifically, it’s the way the bureau collects and records temperatures.

Marohasy works for the Institute of Public Affairs which, if you want to talk about tentacles, is firmly attached to the body of conservative “free market” groups around the world that deny the risks of human-caused climate change.

Last week, I interviewed former BoM director Rob Vertessy, who described the attacks from a “fever swamp” of climate science denial as being baseless, a waste of time, and dangerous, especially when they’re amplified by Rupert Murdoch’s newspaper The Australian.

“As the costs of climate change accumulate in the years ahead,” Vertessy said, “I can see that leaders of this climate change denial movement will really be seen as culpable.”

Institute of Public Affairs Tentacles

Marohasy has been pursuing the bureau with claims of “corruption” and “propaganda” since at least 2014.

Marohasy claims to have found genuine, substantive problems with the BoM data and that these problems undermine the credibility of the data that shows Australia has warmed about 1°C since the start of the 20th century.

So let me explain why it’s not on the front page of the newspapers, why there is no scandal, and how the bureau’s data has largely stood up to scrutiny.

First, Marohasy’s “criticisms” of the bureau’s data have been mostly fixed on a dataset known as ACORN–SAT — a temperature record that goes back to 1910 using data from 112 locations.

That data shows that Australia’s five hottest years on record have all happened since 2005 (starting with the hottest, the list goes 2013, 2005, 2014, 2016, 2009).

Homogenize This

There are two elements of the ACORN–SAT data that Marohasy has tried to argue against. Let’s take them in turn.

Marohasy says the bureau has data going back much further than 1910 (which it does) and that this would show that Australia was warmer back then than it is now, if only the bureau would include it.

In a letter to Senator John Birmingham in March 2014, Marohasy wrote: “But inclusion of this data into the official Australian temperature record would likely show that the years of the Federation Drought (1896 to 1902) were as hot, or hotter than temperatures now.”

A Berkeley Earth reconstruction of temperatures across Australia since the late 19th century

Marohasy, like other global warming deniers, also attacks a method used by the BoM and other major climate and weather agencies around the world (and by the Berkeley project) that’s known as homogenization.

ACORN–SAT is a homogenized dataset. Homogenization takes account of changes in individual weather monitoring stations that can have an impact on the temperature recordings.

An example might be a temperature station being moved to a cooler spot, or buildings or vegetation changing around a site. If you were interested in changes relevant to the climate, then you would not want to introduce non-climatic errors into your data.

Professor Neville Nicholls of Monash University has explained why these adjustments matter and how ignoring clear problems with data isn’t how science is done.

Dr. Lisa Alexander, an associate professor at the University of New South Wales who deals with global datasets all the time, has told me: “Is the bureau fiddling the figures to fit with a global warming conspiracy? No! Are they amending the records to make them consistent through time? Yes.”

But in any case, what impact does this data homogenization have on Australia’s climate record. If you didn’t do it, would the story change?

Well, the bureau runs another long-term dataset called AWAP and this uses unhomogenized temperature measurements from about 700 stations.

In a parliamentary hearing in 2014, Senator Matt Canavan asked then BoM director Rob Vertessy about this AWAP dataset and how its temperature results compared to ACORN–SAT.

Between 1911 and 2013, there was a 0.01°C difference in the average annual temperatures shown between the two. Here’s the comparison on a chart.

Two Australian climate datasets compared: AWAP and ACORN-SAT. Credit: Bureau of Meteorology

Considering that Australia has warmed by about 0.9°C since 1910, all of this means that whether you use homogenized or unhomogenized data, it really makes no difference.

Marohasy has also been claiming that because two of the bureau’s temperature stations had a fault that caused them to stop working at temperatures below -10.4°C, that this also undermined Australia’s clear warming trend (even though the temperature stations in question are not part of the ACORN–SAT dataset anyway).

There has been an inquiry into these claims, with three external experts joining two internal BoM staff. In short, the inquiry found the issue had no direct or indirect impact on Australia’s ACORN–SAT temperature record.

On the review’s release, energy minister Josh Frydenberg said: “The Australian people have been well served by the bureau and can continue to rely on the excellent services it provides.”

The report is the latest in a string of reviews of Australia’s temperature record. There was a 2011 expert panel that led to the establishment of a technical advisory forum that has just completed its third and final report.

That report says: “The Forum remains satisfied with the Bureau’s ongoing development and operation of the ACORN–SATdataset, and notes that the Bureau has consistently demonstrated a genuine commitment to best-practice management of the dataset.”

But Australia’s network of climate science deniers continue to grasp at straws, despite their arguments being inconsequential to the record-breaking temperatures across Australia and despite multiple technical inquiries refuting their claims.

That’s why it’s a non-scandal and might also be why the story is not getting attention outside the fever swamp.

10 Comments

George Darroch 1 year ago

They lie, without the slightest shame. I’m convinced that *nothing* will have any impact on their flat-earth belief system.

Farmer Dave 1 year ago

While you are right about their lying, George, because they “know” they are right, they would not see themselves as lying. To them, it is the rest of us – people convinced by the evidence – who are the people who lie. Alas, you are probably right about their belief system.

Joe 1 year ago

…and the Sun revolves around the Earth. Look, science and facts matter not a jot to these jokers. Tell a lie often enough and the non thinking punters out there will believe it ( the lie ) is the truth and nothing will sway them.

Joe 1 year ago

The ‘fever swamp’ of Rupert’s newsrags, The IPA and of course The COALition…desperate times, desperate measures !

Vicki Stevens 1 year ago

Yep, those with most to lose shout loudest propaganda, and those paid by those who have must to lose, spruik their propaganda louder still to keep their pay packets #Alan Jones

Joe 1 year ago

Vicki, forgive me, I forgot to give a ‘plug’ as well to the radio shock jocks…the Jones , the Hadley, the Smith etc. It is there for all to see. They talk nonsense rubbish and lo and behold the listeners believing what they hear, ring in to Jonesy and friends and its….. ‘War against RE’.

Stephen Gloor 1 year ago

I was on her blog 10 years ago and well remember the swamp dwellers there. Hissink and Graham spring to mind as the most odious. Morohasy is not a climate scientist and then had real problems grasping the basics. Don’t think she has improved. BTW for any swamp dwellers that read this I was Ender – you will remember.

The_Lorax 1 year ago

I remember. Your house burnt down and is being rebuilt BTW.

Ken Dyer 1 year ago

2 out of 114 automated temperature recording stations failed, and were replaced with better units. That is a 1.75% failure rate, for a very short period of time, and one would think, well within the parameters for forecasting weather and for any other statistic for that matter. When one considers that there is probably a 100% chance that Senator Roberts is a British citizen, one begins to understand the delusional world these people live in.

Brian Tehan 1 year ago

If you increase the amount of co2 in the atmosphere by 40%, as we have, the planet’s temperature will go up. We’ve known this since the 1850s. Improving science and computational capabilities can make this prediction more accurate and detailed. The climate records verify the predictions. It would be much more surprising if we were to find that the temperature wasn’t increasing. The harassing of the BOM is part of the misdirection of the fanatical science deniers.